I was two years out of school working on C# and WPF when I was tasked with writing an iOS app. My first steps to gain knowledge of the syntax/structure/etc of the language was to watch the Standford CS139p lectures (http://itunes.apple.com/itunes-u/ipad-iphone-application-dev...). I only had to watch the first six or so before I had a good knowledge of the language and the starting point of UIKit. From that point I just started brute forcing it.

Reading Apple's documentation was the fastest way for me to ramp up and they actually include a lot of really useful examples. Even lower level things like CoreGraphics have some in depth examples which will probably be what you need for your "Flipboard" like interactions.

Because I do so much iOS dev I have my own "library" I now use for every project. But it was cobbled together over a couple years and inspiration was taken from many open source projects.

If you need to make web requests in your app (which basically every app should) ASIHTTPRequest is an interesting framework. https://github.com/pokeb/asi-http-request. I took the idea behind this and distilled it down to something that was much simpler which is what I needed. ASIHTTPRequest is sorta the kitchen sink of web request clients.

If you need a relational database in your app, sqlite is a simple include away. There are a lot of wrapper frameworks out there but I didn't use any of them. I wrote my first app directly accessing the C API and then wrote my own wrapper framework for it. Because I had never used SQLite before needed it in iOS it helped me learn a lot more about it.

One thing I'd point you to is my collection of Categories and Macros that I put into every project https://github.com/reidmain/Objective-C-Categories-and-Macro.... Specifically pay attention to FDIsNullOrEmpty, NSObject+PerformBlock, UIView+Layout. I use these categories so much that I always include them in my precompiled header file.

That's all good advice, but I'd like to point out that ASIHTTPRequest has been abandoned for about a year now. I think most people have switched to using AFNetworking (https://github.com/AFNetworking/AFNetworking) which came out of Gowalla.

As a nice bonus, AFNetworking doesn't require you to implement delegates but instead allows you to use blocks, which simplifies things somewhat.

I think I got the kindle version for $22. It is perfect. Just released a little over a month ago, it uses Xcode 4.3. The first few chapters have no iOS stuff as they bring you up to speed on Obj-C and from there you start building the bases of iOS.

I love that they make you strip out all the code from the iOS templates and make you do it yourself. It really is a structured learning experience rather than just an information dump.

I'm only about 1/3 the way through so far - but so far it's been exactly what I needed.

For your level of experience I would go would go with Kochan - Programming in Objective-C 4th edition.

There is also a free course for iPhone programming from Stanford (video lectures).

MonoTouch is a good alternative if you prefer to use C#, but you will need to pay 99$/year to Apple + 399$ for Monotouch. The good thing is that you can evaluate MonoTouch and pay after you are comfortable with the tool.

RubyMotion is too young to be used in a large application. Also learning Ruby and Cocoa in the same time can be difficult. I think RubyMotion is a good fit for an experienced Ruby programmer that wants to start coding on iOS. Another potential problem with RubyMotion is that it is currently developed by a single person, which can be problematic on long term.

That been said, muy advice is to go on the Objective-C route since you are already comfortable with C. Objective-C is a small language and an experienced C programmer can be up to speed in a matter of days.

The real challenge is in learning the iOS libraries and not the programming language.

I can not agree with recommending ARC to anyone at this time; in this case there is a ton of existing code out there which is incompatible with it. If you are an experienced obj-c developer who's tired of writing boilerplate and uses the static analyzer with LLVM - then go for it.

Learning to clean up after yourself is a life skill worth having. And besides, there's always the -fobjc-arc flag for classes which use it.

I suggest you to do a search after iOS 5 on Amazon and check the comments before buying a book. I'd stay away from any of the Appress books on Objective-C, iOS, etc ... low quality of information and a lot of typos.

Personally I don't have a preferred source and I tend to use Apple's documentation or tutorials from websites like:

I'd say there's no quick way to do it, the message passing of obj-c is very different than the event-based slots & signals programming you are used to. And that's before the hell-which-is-InterfaceBuilder. Since you already familiar with programming, I'd suggest the Big Nerd Ranch guides at bignerdranch.com

Most online examples won't give you the details about the important stuff - single inheritance vs. categories, delegates and message passing in the runtime, extending a protocol, etc. You may see it in the code, but there won't be any theory or reasoning behind it to help you.

As a side note, you can track your learning progress by how much you hate XCode with specific examples of how it ruined your day.

Can't speak to clutch.io, but the other 2 just seem to get in the way of someone who already knows Ruby, C#, and obj-c. Do you really need another layer of abstraction if you want to learn something at a lower level?

I second the recommendation of the Big Nerd Ranch guides. They are excellent for learning Objective-C and IOS.

I've been playing around with Ruby Motion for the past two days and since I am pretty experienced with Ruby already, I'm finding it helpful for learning ios concepts. However, if you don't have any experience with Ruby I would recommend just starting with Objective-C and xcode.

Apple's recommendation is to start using it today. Retain/Release patterns always took newcomers a long time to master, and it distracts from building applications. In Apple's own words, it's a compiler's problem – shouldn't be yours.

Started iOS dev about a year ago. Hvaent written dozens of apps some with very custom UI elements.
Don't bother with clutch.io/rubymotion/mono touch. Learn the raw Objective-C/Cocoa-Touch APIs. Especially for something UI intensive like flipboard.
Check out Standford iOS programming lectures. They are on Youtube and iTunes (for free).

Can anyone specify the absolute minimum requirements I should be asking for if I'm looking for a dev Mac on craigslist or the like?

As a (mostly) web developer there's a good chance I'd build most of my app in HTML/CSS using something like PhoneGap and only do the final compile step on the Mac. A) Does that sound like a good plan? B) Does that impact significantly on the minimum system requirements?

I'm not very familiar with how PhoneGap works, and how much it depends on you, but from the docs it seems you still need the classical toolchain.

But anyway, if you want to save yourself some hassle, find something that can run Lion. XCode 4 doesn't run on older OS (or at least not easily), and most current docs are aimed at it (I'm not even sure older XCode versions cover the current iOS versions).

So, you need at least something with a Core2Duo. Older Core Duo might work, I'm not sure. I have some old white Macbook (13" from 2009), who mostly does the job. Not blazing fast, but since I only use it for iOS development, it's enough.

Make sure you get something that can run the 64-bit kernel, as this will be a requirement for running Mountain Lion when it comes out this summer. You don't want to be stuck on an older OS, as Apple quickly stops supporting them for the latest developer tools. Which models support the 64-bit kernel is not obvious, as it is not the same thing as simply having a 64-bit processor.

A list of Macs that will probably support Mountain Lion is available here:

Beyond that, you want at least 4GB of RAM, with 8GB or even 16GB preferred (Xcode is a severe memory hog), especially if you get a spinning platter instead of an SSD.

I would strongly recommend against something like PhoneGap. iOS users generally don't appreciate non-native interfaces, and it will be extremely hard to achieve the necessary level of polish with HTML/CSS. If you want to use HTML, then you probably might as well just go straight to building a real web app. If you want native apps, it's worth your while to use the native language and tools.

Thanks for the insight re: PhoneGap and native interfaces. Does the same apply to Appcelerator (or similar)? It compiles to native, but does the interface feel native or HTMLy? At some point I want to play around some, but that requires buying a mac and an iThing, neither of which I have yet.

Re: system requirements - that sucks that I really need to have (moderately) up to date hardware to do iOS development. On a PC I'd probably be fine with a 2004 Dell laptop with a fresh install of Windows. I guess this is my first "welcome" to the walled garden.